Thanks a lot. I do get you fully now and the processes you described. But the ultimate problem is this, when you press 'DEL' it doesn't enter BIOS setup area so at least you set boot device. It just stays like that. I thought the memtest86 would only boot up when the screen ''Press any key to boot from cd has shown''.i appreciate you efforts. Of course I would try and see if the memtest86 would force the PC to boot from cd or enter setup. Have a good time